Sediment ejection



J. C. SHARP ETAL SEDIMENT EJECTION Filed Nov. 7, 1952 sept. 27, 1955United States Patent O SEDIMENT EJECTION John C. Sharp and KendallClark, Glen Ellyn, Ill., as-

signors to General Electric Company, a corporation of New York Thisinvention relates to centrifugal extraction types of washing machines,and in particular to an improved means for accumulating and ejectingheavy dirt and other foreign objects during the centrifuging operation.

In domestic clothes washing machines in which the clothes are washed,rinsed, and centrifugally damp-dried in a single tub or receptable, thewash water and the one or more rinse waters are removed from the tub andto a large measure from the articles being washed, by rotating the tubat a suitable centrifuging speed. In some machines, the tub wall may beperforated over substantially its entire area, in which event the wateris thrown radially outward in a multiplicity of ne streams.Alternatively, the tub wall may be imperforate except for openings at/or adjacent the line of maximum diameter of the tub. In this latter typeof machine, it is conventional to have the tub wall increase uniformlyupwardly to a zone of maximum diameter near the upper wall thereof, andthe water climbs the wall to 4escape through the discharge openings asthe tub rotates.

Experience shows that in each of these conventional types, heavy dirtsuch as sand and similar particles found in childrens clothes, mechanicswork clothes, and the like, migrates to the bottom of the tub during thewashing operation, but is then trapped by the clothes and held againstejection during the extraction cycle. The perforate tub machines areparticularly susceptible to resoi'ling the washed clothes in this mannerbecause the soil 1s strained through the clothing, and the advantagewhich this type of washing machine tube has overthe imperforate tub typein extracting more water at the same extraction speed is thus offset byinferior washing results.

The present invention provides a washing machine tub of the verticalaxis centrifugal extraction type in which improved means are providedfor trapping the sedimentary dirt and for discharging it from the tubthrough external passages, thus avoiding resoiling the clothes by suchdirt accumulations. A feature of our invention is that we providerelatively largel perforated tub wall areas which increase the speed andefficiency of the extraction while retaining the desirable features offloating light dirt out of the tub through the upper tub wall openingsinstead of straining the dirt through the articles of clothing as in theperforated tub types.

It is therefore a main object of our invention to provide a washingmachine tub having improved water extraction means.

It is another object of our invention to provide a washing machine tubhaving means for? improving water extraction from the washed articleswhile substantially eliminating the resoiling of the articles byproviding passages externally of the tub for the discharge of heavy dirtparticles.

It is a further object of the invention to provide a centrifugalextraction tub for washing machines and the like having a plurality ofvertically extending, relatively wide, outflow channels disposed aboutthe outer wall 'of the tub and communicating with the tub by means of2,718,772 Patented Sept. 27, 1955 perforated cover plates of relativelylarge area through which a substantial portion of the water may iiowinto the channels for removal from the tub.

It is still another object of the invention to provide a washing machinetub with external sediment ejection passages provided with perforatedcover plates which constitute a substantial area of the tub wall and arereadily removable to facilitate cleaning the passages from end to end.

Other features and advantages of our invention will be apparent from thefollowing detailed description of a presently preferred embodiment, readin the light of the accompanying drawings in which:

Fig. l shows in vertical section on lines 1-1 of Fig. 2 the tub portion,agitator, and other structure of a washing machine of the centrifugalextraction type;

Fig. Z is a fragmentary plan section taken on lines 2-2 of Fig. l; and

Fig. 3 is a detail, in vertical section on lines 3 3 of Fig. 2, showingthe forward edge of a cover plate.

We have considered it necessary to show only the tub and water collectorportion of a washing machine, because various types of centrifugalextraction machines are well known and our invention is applicable toany upright axis tub type'. The drive mechanism and arrangement of otherextraneous parts are not shown.

The tub 1 is keyed or otherwise aixed to a tubularI shaft 2, journalledin a ixed frame member 3. Said tub is thus rotatably mounted within anencompassing water collector 4, rigidly secured within an outer framestructure (not shown). lt will be noted that the journal member 3extends through a large coaxial opening 5 in the bottom of the watercollector, thus permitting the rotating tub to gyrate about itssuspension (not shown) when centrifuging an unbalanced clothes load. Aflexible boot 6 seals olf the opening 5 while permitting gyratorymovement, as is well known. An agitator 7 is fixed to a shaft 8journalled within shaft 2. Said shaft is arranged to be oscillated, andshaft 2 rotated, by any conventional drive means (not shown).

The tub wall extends outwardly and upwardly from a central depression orsump 9 and then slopes outwardly in an upward direction to a point ofmaximum diameter suitably below the top of the agitator post. Adjacentsaid maximum diameter zone the tub wall has a multiplicity of wateroutflow openings 10, preferably although not necessarily arranged in asingle-row. Mounted on the top wall of the tub is a heavy annularbalancing mass 11 defining the opening through which the clothes and thelike (not shown) enter the tub. i

As is well known, the tub is filled to an appropriate r level-forexample, a normal water line WL-and the articles are washed by theaction of the agitator, which mechanically agitates the clothes and setsup powerful currents within the tub which causes the clothes to move andturn over in the body of washing liquid. During the washing period,oatable soil extracted from the clothes gathers at the top of the tuband much of it is sloshed through the openings 10. Sand and other heavydirt linds its way to the bottom of the tub where much of it gathers inthe relatively quiescent pool within the sump 9.

After the washing period the agitator is stopped and` the tub rotated ata speed suicient to extract the freeu water and a large amount of thewater entrained within the clothes. The acceleration of the rotating tubduring centrifuging causes the water line to assume approximatelyparabolic curvatures on increasing depth as in` dicated at WL1 and WLZ.Thus, the water climbs the tub wall for discharge through the openings10 into thewater collector. A pump (not shown) is usually provided toempty the water collector. A usual washing machine.

cycle may include the wash operation and several rinsing operations, atleast one of which may be accompanied by agitator action to free thearticles of any soap curd, heavy dirt, and the like which may havecollected thereon during the previous washing operation.

It has previously been proposed to provide separate escape passages forthe heavy sedimentary dirt to reduce the contact of the dir-t with thelaundered articles during the centrifuging operations. In Castner U. S.Patent 2,470,140, of May 17, 1949, for example, small diameter tubes areprovided on the outside wall of an imperforate tub. Such tubes aresubject to clogging with lint and the like and are diflicult to clean.

We provide dirt-ejection passages which have a large ow capacity andarrange said passages with removable cover plates to make it easy forthe user to clean the passages. The said cover plates form perforatedtub wall areas which increase the efficiency of centrifugal extraction.

In the presently preferred embodiment of our invention, we form the tub1 with a plurality-for example, two, three, or four-of relatively widechannels 12, each terminating in an open discharge mouth 14 just belowthe row of water discharge openings 1li. The lowermost end of eachchannel is in effect a continuation of the bottom wall of the tub at thesump portion thereof; and thus the side Wall 15 dening the sump isperiodically interrupted, as best appears in Fig. 2.

The channels form sediment ejection passages when provided with theperforated cover plates 16. As shown in Fig. 2, the cover plates haverearwardly projecting anges 17 which t snugly against the sides of thechannels. Said langes may be continuous or interrupted, their primarypurpose being to position and support the covers within the channelwalls. We prefer to divide the wide channels, and accordingly providethe cover plates with a central rib 18 which reaches to the rear wall ofthe channel. The cover plates are secured relative to the associatedchannels in a manner to permit their easy removal by the user forperiodic cleaning. Because of the snug seating of the covers within thechannels, the securement may be simply accomplished by an eccentriclatch member 20 rotatably mounted on a suitable stud 21 passing throughthe bottom wall of the tub. The latch member is rotatable into or out ofengagement with a locking wall 22 projecting from the shoulder 23 of thecover plate. Said locking wall is contigurated to lie along the bottomof the sump portion of the tub and its forward edge is preferablyrounded to reduce the obstruction to the outward movement of thesediment. At its upper end the edge of the cover plate abuts the bottomwall of the balance ring 11. lt is not considered necessary to latch orotherwise fasten the upper end of the cover plates.

Over the area from the break of shoulder 23 to substantially the planeof the openings 10, the cover plates are formed with a multiplicity ofinow ports 24. These ports are purposely of small diameter'so as toprevent the entry or entrapment of small buttons or the like which maybe on a garment being washed. Through the forward shoulder walls, weprovide narrow elongated slots 25 also dimensioned to avoid catchingbuttons or the like during thewashing operation or any latercentrifuging steps.

While the articles are being agitated during the Washing and anysubsequent agitate-rinse periods, the water currents within the tub andthe movement of the articles therein will keep even heavy particles ofloose dirt in suspension for some time. A quantity of it will gravitatedirectly to the central sump portion; other portions may move outwardlyand downwardly passing along the inner wall of the tub. Any of the dirtwhich moves downwardly along the cover plates 16, which are flush withthe tub walland. therefore may beconsidered to be a part of the tubwall, may enter the channels 12 directly through the openings 24 andwill accumulate in the very gently sloping base portion 26 of thechannels.

Assuming an accumulation of heavy dirt particles in the sump 9 and thelower part of the channels at the commencement of a spin operation,centrifugal forces will cause the particles to move outwardly andupwardly. Those already within a channel will move with the water streamupwardly through the channel and will be discharged with the water intothe water collector. Dirt which has gathered in the sump will moveoutwardly through the openings 25 for similar discharge. By making theside Wall 15 of the sump relatively steep and carrying the bell 7.1 ofthe agitator into rather close proximity to the sump wall, we reduce thereturn of any dirt particles into the tub at the sump areas betweenadjacent channels. This dirt should work its way around the sump duringthe early centrifuging stage when there is still a substantial depth ofwater above the sump and will eventually be caught by the water streamsentering the channel ports 25 to be conveyed thereby into the channelsfor discharge therefrom.

As centrifuging continues and the water line assumes a shape leaving thesump dry,` the direct inow of Water into the channels through the ports24 will continue to Convey into the channels any dirt particles whichmay not have reached the sump. In addition, the perforated cover platearea provides a direct escape for liquid entrained in the particleswithin the tub rather than requiring the liquid to climb the tub wall tothe level of the outilow ports 10. When it is considered that at thelater stages of centrifuging the articles become relatively tightlyplastered against the tub wall, it is apparent that the articlesinterfere with the passage of Water to a considerable extent. Ourconstruction, therefore, facilitates the extraction of water whilenevertheless permitting to a much greater extent than in the usualperforated tub the flotation of light soil through the openings 1t).

While there has been described what are at present considered to be thepreferred embodiments of the invention, it will be understood thatvarious modifications may be made therein, and it is intended to coverin the appended claims all such rnodications as fall within the truespirit and scope of the invention.

We claim:

l. A washing machine of the centrifugal extraction type, comprising asmooth-walled tub adapted to receive washing liquid to a predeterminednormal level, said tub being imperforate below said liquid level, meansfor mounting said tub for rotation about an upwardly extending axis, andan agitator disposed within said tub and having a substantially circularbase portion disposed at the bottom of said tub concentric with the axisof rotation thereof; said tub having a substantially circular, shallowsump formed in the bottom wall thereof, said sump being delined by anupstanding outer wall extending about the base of said agitator in closeproximity thereto, the bottom portion of said tub then extendingoutwardly and upwardly from the upper edge of said sump wall and curvingupwardly to form a side Wall which extends upwardly and outwardly withgradually increasing diameter to above said normal liquid level; saidtub bottom and side walls being formed with a plurality of inwardlyfacing sediment-ejection channels in symmetric disposition relative tothe axis of rotation of said tub, the base wall of each channelcomprising an uninterrupted extension of said sump bottom wall andfollowing the contour of the bottom and side wall portions of said tubto terminate in an open end above said normal liquid level; and a coverremovably disposed in each said channel, said covers having a forwardwall portion effecting substantially a continuation of said sump outerwall, said forward wall portion having at least one opening disposedwithin the sump for direct communication between said sump and channel,and a plurality of openings disposed throughout the remainder of saidcover, whereby said channels and their respective covers providesluiceways leading outwardly and upwardly from said sump andcommunieating directly with said sump and with the interior of said tub.

2. A washing machine according to claim 1, in which each said cover hasa septum extending the length thereof and reaching substantially to thebase of the associated channel to provide a pair of sluiceways, saidcover forward wall portion having an opening on each side of saidseptum.

3. A washing machine according to claim 1, in which the forward wallportion of each said cover has a forwardly projecting lip in surfacecontact with said sump bottom, and said sump has a locking memberrotatable into engagement with said lip to secure the end of said coverreleasably against said sump bottom.

References Cited in the le of this patent UNITED STATES PATENTS

